Before the M cameras and their faster lenses, or today’s astronomic digital ISO numbers, photographers had to contend with the same low light conditions as now, but with slow film speeds and lenses with smaller apertures. Yet they did pretty well with their older cameras. One of the ways they did this was by steady handholding at slow shutter speeds.
The older model SM Leicas had slow speeds which were quiet and smooth in action, and the smaller camera bodies allowed the backs of both hands to be held close together tight against the face. Without a large viewing window to be avoided at the left end, or a winding lever sticking out on the right, the smaller camera bodies allowed more ways for the backs of the hands to be pressed tightly against the face to keep the camera just as steady as the head could be held still. 1/20th of a second was a normal handholdable speed with a normal lens in those days. On the earlier cameras there was a gap between 1/2oth and a less hanholdable 118th, which often meant a small tripod.